Thanks everyone for the info. We've previously had amps that heated the entire upstairs of our apartment, as well as running up the electricity bill. I think if we had more space, and a quieter AC system, I'd jump at the chance to hear the OTL's. The only one I've heard represents merely a toe dip into the pool of OTL's. Jax2 came through last year with his Berning MicroZOTL, and we ran it through our Klipschorns. Understandably, it's 1 watt didn't lend much weight to the music, but oh my did the vocals sound delicious.
